The invention relates to a cooling apparatus. In a known cooling apparatus (U.S. Pat. No. 3,974,857), the cooling circuits are controlled by means of stopcocks to be operated manually, it being possible to read off the approximate cooling requirement on scales indicating the suspension level of suspension bodies in vertical glass tube sections of the cooling circuits.
It was found in tests that the variation in the weight and dimensions of the moldings from one injection mold depends on the temperature constancy in the critical zones of the injection molding machine to a substantially higher degree then previously assumed and, in particular, on the temperature constancy of the injection mold and of the feed zones for feeding the granules into the plasticizing cylinder as well as on the temperature constancy of the pressure oil in the hydraulic circuit.